A Novel Environment-Friendly Adhesive Based on Recycling of Broussonetia papyrifera Leaf Forestry Waste Protein

Abstract

Wood adhesive was prepared using Broussonetia papyrifera waste leaf protein as the raw material. The performance of the B. papyrifera leaf protein adhesive compared to soy protein was investigated using X-ray diffraction, Fourier transform infrared spectroscopy, and differential scan-ning calorimetry. The results indicated that both B. papyrifera leaf protein and soy protein were spherical proteins that could easily form three-dimensional crosslinked network structures and were of potential for protein adhesive preparation. The B. papyrifera leaf and soy protein-based adhesives had similar curing behaviors, but the crosslinking reaction of B. papyrifera leaf protein-based adhesive seems to be more complex than that of the soy protein-based adhesive. The B. papyrifera leaf protein-based adhesive had a lower increasing trend of particle size and crystallinity than the soy-based protein adhesive, and its water resistance and bonding strength were also weaker. The plywood with BP leaf protein adhesive had dry and wet shear strengths of 0.93 MPa and 0.59 MPa, respectively. These results are promising for future industrial production using Broussonetia papyrifera waste leaf protein as a new protein wood adhesive in the wood industry.